bluechalking

Bookmarklets | MOVABLE TYPE
Via mbites :
" Bluechalking is the invented-by-me-but-as-yet-non-existent-practice of marking a Bluetooth symbol on sidewalks/pavements and walls to indicate that someone with a Bluetooth-enabled phone is often in the area, using the Bluetooth symbol (below) and your phone's 'name'.

The idea would be to explore an entirely new kind of wireless social interaction. A kind of consensual Bluejacking. "